[GR-15078] Throw syntax error if nonlocal statement is used after local declaration.

PullRequest: graalpython/674

Author: ppisl

doc/CONTRIBUTING.md

@@ -149,6 +149,11 @@ debugger or Chromium, respectively.
         graalpython/com.oracle.graal.python.test/src/tests/test_tagged_unittests.py \
         -k NAME-OF-CPYTHON-UNITTEST
 
+A tag file can be regenerated with
+
+    mx python graalpython/com.oracle.graal.python.test/src/tests/test_tagged_unittests.py \
+        --retag NAME-OF-CPYTHON-UNITTEST
+
 There's also multiple other gates that may fail with changes. One of these is
 our *style* gate, which checks formatting rules and copyrights. To auto-fix most
 issues, run the following command. Anything that's reported as error after this

graalpython/com.oracle.graal.python.test/src/com/oracle/graal/python/test/parser/AssignmentTests.java

@@ -196,4 +196,16 @@ public void assignToLiteral05() throws Exception {
     public void assignToKeyword01() throws Exception {
         checkSyntaxErrorMessage("True = 1", "SyntaxError: can't assign to keyword");
     }
+
+    @Test
+    public void nonLocal01() throws Exception {
+        checkSyntaxErrorMessage(
+                        "def outer():\n" +
+                                        "  x = 'local in outer'\n" +
+                                        "  def inner():\n" +
+                                        "    x = 10\n" +
+                                        "    nonlocal x\n" +
+                                        "  inner()\n",
+                        "SyntaxError: name 'x' is assigned to before nonlocal declaration");
+    }
 }

graalpython/com.oracle.graal.python.test/src/tests/unittest_tags/test_fstring.txt

@@ -7,6 +7,7 @@
 *TestCase.test_del
 *TestCase.test_dict
 *TestCase.test_double_braces
+*TestCase.test_empty_format_specifier
 *TestCase.test_if_conditional
 *TestCase.test_invalid_expressions
 *TestCase.test_literal

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/builtins/Python3Core.java

@@ -168,6 +168,7 @@
 import com.oracle.graal.python.runtime.PythonParser;
 import com.oracle.graal.python.runtime.PythonParser.ParserMode;
 import com.oracle.graal.python.runtime.exception.PException;
+import com.oracle.graal.python.runtime.formatting.ErrorMessageFormatter;
 import com.oracle.graal.python.runtime.object.PythonObjectFactory;
 import com.oracle.truffle.api.CallTarget;
 import com.oracle.truffle.api.CompilerDirectives.CompilationFinal;
@@ -679,7 +680,15 @@ public RuntimeException raiseInvalidSyntax(Node location, String message, Object
         instance.setAttribute("text", section.isAvailable() ? source.getCharacters(section.getStartLine()) : "");
         instance.setAttribute("lineno", section.getStartLine());
         instance.setAttribute("offset", section.getStartColumn());
-        instance.setAttribute("msg", section.getCharIndex() == source.getLength() ? "unexpected EOF while parsing" : message != null ? message : "invalid syntax");
+        String msg;
+        if (section.getCharIndex() == source.getLength()) {
+            msg = "unexpected EOF while parsing";
+        } else if (message != null) {
+            msg = (new ErrorMessageFormatter()).format(message, arguments);
+        } else {
+            msg = "invalid syntax";
+        }
+        instance.setAttribute("msg", msg);
         throw PException.fromObject(instance, location);
     }
 }

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/parser/PythonNodeFactory.java

@@ -41,8 +41,6 @@
 
 package com.oracle.graal.python.parser;
 
-import com.oracle.graal.python.PythonLanguage;
-
 import com.oracle.graal.python.builtins.PythonBuiltinClassType;
 import com.oracle.graal.python.builtins.objects.function.PArguments;
 import com.oracle.graal.python.builtins.objects.function.Signature;
@@ -86,9 +84,11 @@ public final class PythonNodeFactory {
     private final NodeFactory nodeFactory;
     private final ScopeEnvironment scopeEnvironment;
     private final Source source;
+    private final PythonParser.ParserErrorCallback errors;
 
-    public PythonNodeFactory(PythonLanguage language, Source source) {
-        this.nodeFactory = NodeFactory.create(language);
+    public PythonNodeFactory(PythonParser.ParserErrorCallback errors, Source source) {
+        this.errors = errors;
+        this.nodeFactory = NodeFactory.create(errors.getLanguage());
         this.scopeEnvironment = new ScopeEnvironment(nodeFactory);
         this.source = source;
     }
@@ -135,6 +135,11 @@ public SSTNode registerGlobal(String[] names, int startOffset, int endOffset) {
     public SSTNode registerNonLocal(String[] names, int startOffset, int endOffset) {
         ScopeInfo scopeInfo = scopeEnvironment.getCurrentScope();
         for (String name : names) {
+            if (scopeInfo.findFrameSlot(name) != null) {
+                // the expectation is that in the local context the variable can not have slot yet.
+                // The slot is created by assignment or declaration
+                throw errors.raiseInvalidSyntax(source, createSourceSection(startOffset, endOffset), "name '%s' is assigned to before nonlocal declaration", name);
+            }
             scopeInfo.addExplicitNonlocalVariable(name);
         }
         return new SimpleSSTNode(SimpleSSTNode.Type.EMPTY, startOffset, endOffset);
@@ -210,7 +215,7 @@ public YieldExpressionSSTNode createYieldExpressionSSTNode(SSTNode value, boolea
         return new YieldExpressionSSTNode(value, isFrom, startOffset, endOffset);
     }
 
-    public Node createParserResult(SSTNode parserSSTResult, PythonParser.ParserMode mode, PythonParser.ParserErrorCallback errors, Frame currentFrame) {
+    public Node createParserResult(SSTNode parserSSTResult, PythonParser.ParserMode mode, Frame currentFrame) {
         Node result;
         boolean isGen = false;
         Frame useFrame = currentFrame;

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/parser/PythonParserImpl.java

@@ -72,7 +72,7 @@ private static Python3NewParser getPython3NewParser(Source source, ParserErrorCa
         lexer.addErrorListener(Builder.ERROR_LISTENER);
         Python3NewParser parser = new Python3NewParser(new CommonTokenStream(lexer));
         parser.setBuildParseTree(false);
-        parser.factory = new PythonNodeFactory(errors.getLanguage(), source);
+        parser.factory = new PythonNodeFactory(errors, source);
         parser.removeErrorListeners();
         parser.addErrorListener(Builder.ERROR_LISTENER);
         parser.setErrorHandler(new PythonErrorStrategy());
@@ -145,7 +145,7 @@ public Node parseN(ParserMode mode, ParserErrorCallback errors, Source source, F
         FrameDescriptor inlineLocals = mode == ParserMode.InlineEvaluation ? currentFrame.getFrameDescriptor() : null;
         // ANTLR parsing
         Python3NewParser parser = getPython3NewParser(source, errors);
-        parser.factory = new PythonNodeFactory(errors.getLanguage(), source);
+        parser.factory = new PythonNodeFactory(errors, source);
         SSTNode parserSSTResult = null;
 
         try {
@@ -181,7 +181,7 @@ public Node parseN(ParserMode mode, ParserErrorCallback errors, Source source, F
         }
 
         lastGlobalScope = parser.factory.getScopeEnvironment().getGlobalScope();
-        return parser.factory.createParserResult(parserSSTResult, mode, errors, currentFrame);
+        return parser.factory.createParserResult(parserSSTResult, mode, currentFrame);
 
     }
 
@@ -258,6 +258,9 @@ public String unescapeJavaString(String str) {
     }
 
     private static PException handleParserError(ParserErrorCallback errors, Source source, Exception e) {
+        if (e instanceof PException) {
+            return (PException) e;
+        }
         SourceSection section = PythonErrorStrategy.getPosition(source, e);
         // from parser we are getting RuntimeExceptions
         String message = e instanceof RuntimeException && e.getMessage() != null ? e.getMessage() : "invalid syntax";